This disclosure relates to patterning thin films and various layers on a substrate. Such patterning includes patterning for fabricating semiconductor devices within a photolithographic patterning scheme.
In material processing methodologies (such as photolithography), creating patterned layers comprises the application of a thin layer of radiation-sensitive material, such as photoresist, to a working surface of a substrate. This radiation-sensitive material is transformed into a patterned mask that can be used to etch or transfer a pattern into an underlying layer on a substrate. Patterning of the radiation-sensitive material generally involves exposure by a radiation source through a reticle (and associated optics) onto the radiation-sensitive material using, for example, a photolithography system such as a scanner or stepper tool. This exposure can then be followed by the removal of irradiated regions of the radiation-sensitive material or non-irradiated regions using a developing solvent depending on a photoresist tone and developer tone. This mask layer may comprise multiple sub-layers.